The boxer short is a relatively complex article as it is intended to cover the low part of the trunk as well as the top part of the thighs over a sufficient length. It comprises a panty portion ended at its upper portion by a belt positioned at the waist, and at its lower portion by two lapels separately positioned on the thighs. It is commonly made from a knitted tube corresponding to a diameter allowing to seamlessly dress the low part of the trunk, and is equipped during a confection operation of a sewn crotch bottom allowing to link the two tubes dressing the thighs. We know how to knit on the circular machines such as the machines SANTONI of SM8-8 type, for example for diameters comprised between 10 and 16 inches (between 25 and 40 cm), tubes intended for of the confection of boxer shorts with a double belt in the top portion and a double lapel in the low portion, this tube may be knitted in both directions (belt-lapel or lapel-belt). We also know the confection of the tube bottom to make the low part of the boxer short, with an attached bottom which can be made on the same type of knitting machine. According to the known prior art of documents US2000073 and FR2805285, the crotch bottom or gusset is a substantially rectangular piece which is put between the edges of two slots or incisions performed at the front and at the back of the knitted tube. The enclosed FIGS. 1 to 3 show in more detail this confection operation. The boxer short 101 is made in the shape of a knitted tube, with an upper belt 102 and a lower border 103, where lapels or reinforcements corresponding to future thigh passages are formed or may be formed. The knitted tube 101 comprises a front face 105 and rear face 106 (in one piece since it is about a circular knitting). The portion 104 intended to form the front pocket of the boxer short intended to maintain the genitals is represented by hatching on the front face 105. We proceed (FIGS. 1 and 2) to a cutting operation creating an incision 107 at the front part 105 and an identical or different incision 108 at the back 106 of the knitted tube, in the middle, at its lower portion. The incision 107 has edges 110, 111 and the incision 108 has edges 112, 113. Each incision 107, 108 is then laterally spaced apart and stretched, as suggested by the arrows of FIGS. 1 and 2, so as to put substantially, in the extension of one another, the edges 110, 111 on the one hand and 112, 113 on the other hand, and form thus substantially rectilinear bottom lines which are sewn together by means of a substantially rectangular crotch bottom 115 (called here “bottom lines” the lower edges of the front and the back of the tubular knitted fabric, intended to be sewn to one another, between the thigh passages, directly or by means of additional pieces of crotch bottom such as the gusset). The document FR2805285 had represented an improvement compared to the classical confection by providing bottom lines with a different length at the front and at the back and by making the crotch bottom 115 with different elastic zones at the front and at the back. This suggestion has allowed to partially solve an often encountered problem with this type of garment, namely the absence of wearing comfort, related in particular to the presence of troublesome seams at the crotch and/or to a bad conformation of this bottom to the anatomy of the wearer, and more particularly to the presence of troublesome seams on the front at the genitals, in particular for man. However, the wearing comfort remains to improve further and this is the purpose of the present invention. More precisely, it is about finding a new method for the confection of the crotch, remaining simple, but leading to an improved comfort.
We know, from the documents WO 2012087210 and WO 2011008138, two methods for the confection of boxer shorts from two knitted rectilinear strips which are applied one on the other. These documents teach that it is possible to tie the two strips together according to some patterns of parallel or T lines which are then incised, so as to give rise to particular crotch shapes. These two methods do not relate to the confection of the boxer shorts from tubular knitted fabric and do not give transposable teaching to this manufacturing method.